Sorry if this is a dumb question. But this has been bugging me.
It is my understanding that speakers run on AC, and the oscillations are what enable them to vibrate and produce sound. Two wires to a speaker, with the current alternating between each wire, and hence neither one is strictly + or - polarity. And supposing that headphones are miniature speakers, it follows that they would run on AC also.
However, the typical unbalanced stereo headphones are powered through a TRS plug. So 3 conductors: left channel signal, right channel signal, and a shared ground channel. If this was AC, then half the time we would be getting the L and R channels mixed together from being sent up to the headphones through the same ground wire. In other words, epic crosstalk or even mono sound. But this has not been my experience.
Can someone enlighten me, please?